So says writer-director Matt Ross’s heartfelt and moving road movie that goes back to nature to rediscover a bucolic time before television, smart phones and social media poisoned precious rituals like eating together around a dinner table.

Captain Fantastic is a bittersweet meditation on the perils of modern parenting, anchored by a tour-de-force lead performance from Viggo Mortensen as a straight-talking father, whose unconventional methods of nurturing his offspring might be considered abuse by outsiders.

“Power to the people - stick it to the man!” he counsels his children, who hone their survival skills and are blessed with made-up Christian names so they are unique in a world of slavish conformity.

On the surface, the family’s makeshift camp in the forests of the Pacific Northwest looks like paradise, but fissures appear when two of the boys clash with their old man about the harsh consequences of living in seclusion.

“Unless it comes out of a book, I don’t know anything!” despairs the eldest son, whose rites of passage include tucking into the heart of a freshly slain wild deer.

Viggo Mortensen as Ben

This tussle between idealism and sobering reality provides Ross’s picture with its narrative thrust and tearful outpourings of raw emotion.

Ben Cash (Mortensen) and his wife Leslie (Trin Miller) raise their six-strong brood in relative isolation so the children won’t be tainted by capitalism or organised religion.

The youngsters - Bodevan (George MacKay), Kielyr (Samantha Isler), Vespyr (Annalise Basso), Rellian (Nicholas Hamilton), Zaja (Shree Crooks) and Nai (Charlie Shotwell) - learn to live off the land and fire their imaginations by reading classics like The Brothers Karamazov and Middlemarch.

Alas, Leslie has bipolar disorder and she eventually takes her own life while undergoing treatment at a hospital.

Ben wants to take the children to the funeral, but Leslie’s father Jack (Frank Langella) forbids him from attending.

“Grandpa can’t oppress us,” argues Zaja and the family boards their ramshackle bus, christened Steve, and heads to New Mexico to give Leslie the Buddhist cremation she requested in her will.